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 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
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package org.apache.http.impl.client;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.client.HttpResponseException;
import org.apache.http.client.ResponseHandler;
import org.apache.http.util.EntityUtils;

A generic ResponseHandler that works with the response entity for successful (2xx) responses. If the response code was >= 300, the response body is consumed and an HttpResponseException is thrown. 
 If this is used with HttpClient.execute(HttpUriRequest, ResponseHandler<? extends Object>), HttpClient may handle redirects (3xx responses) internally. 
Since:
4.4/**
 * A generic {@link ResponseHandler} that works with the response entity
 * for successful (2xx) responses. If the response code was &gt;= 300, the response
 * body is consumed and an {@link HttpResponseException} is thrown.
 * <p>
 * If this is used with
 * {@link org.apache.http.client.HttpClient#execute(
 *  org.apache.http.client.methods.HttpUriRequest, ResponseHandler)},
 * HttpClient may handle redirects (3xx responses) internally.
 * </p>
 *
 * @since 4.4
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public abstract class AbstractResponseHandler<T> implements ResponseHandler<T> {

    
Read the entity from the response body and pass it to the entity handler method if the response was successful (a 2xx status code). If no response body exists, this returns null. If the response was unsuccessful (>= 300 status code), throws an HttpResponseException. /**
     * Read the entity from the response body and pass it to the entity handler
     * method if the response was successful (a 2xx status code). If no response
     * body exists, this returns null. If the response was unsuccessful (&gt;= 300
     * status code), throws an {@link HttpResponseException}.
     */
    @Override
    public T handleResponse(final HttpResponse response)
            throws HttpResponseException, IOException {
        final StatusLine statusLine = response.getStatusLine();
        final HttpEntity entity = response.getEntity();
        if (statusLine.getStatusCode() >= 300) {
            EntityUtils.consume(entity);
            throw new HttpResponseException(statusLine.getStatusCode(),
                    statusLine.getReasonPhrase());
        }
        return entity == null ? null : handleEntity(entity);
    }

    
Handle the response entity and transform it into the actual response
object.
/**
     * Handle the response entity and transform it into the actual response
     * object.
     */
    public abstract T handleEntity(HttpEntity entity) throws IOException;

}